Absorbent bandage



g- 4, 1954 v. MILLS 3,143,113

ABSORBENT BANDAGE Filed Aug. 15, 1962 INVENTOR ATTORNEY United StatesPatent 3,143,113 ABSORBENT BANDAGE Victor Mills, Wyoming, ()hio,assignor to The Procter & Gamble Company, Cincinnati, Ohio, acorporation of Ohio Filed Aug. 15, 1962, Ser. No. 217,217 Claims. (Cl.12829tl) This invention relates to an absorbent bandage and moreparticularly to a sanitary napkin comprising a multiplicity of plies ofabsorbent materiaL.

The common shortcoming found in presently used catamenial pads is thatsuch devices fail in use prior to the time that the absorptive capacitythereof is utilized to its fullest extent. The underlying reason forsuch failure is that the menses, upon entering the napkin, tend to seeptoward the sides and ends of the device at substantially the same rateof flow and since the napkin is considerably longer than it is wide, themenses will fiow to the side margins of the napkin prior to reaching theends of the napkin. In order to avoid soiling of undergarments and topromote comfort, it is the usual practice for the napkin to be replacedprior to the time that the side margins of the device become wetted. Atthe time of changing, therefore, substantial areas of the napkin at eachend thereof are still unwetted by the fiuid and consequently asubstantial portion of the absorptive capacity of the napkin is notutilized.

Many arrangements designed to eliminate the undesirable consequences ofside failure of catamenial pads have been proposed in the past. Examplesof such proposed solutions would be the use of moisture impermeableside, bottom and edge enclosures or pouches to support a sanitary napkinin use. Another approach to the solution of the problem (and the onetoward which the present invention is directed) has been an effort tocause the flow of menses to be distributed over a greater area of thenapkin. To date it appears that none of the prior art solutions haveattained the practical or commercial success intended. In some cases,the devices were too expensive, others were uncomfortable and in somecases the solutions were unworkable.

It is an object of the present invention to obviate the abovediificulty.

Another object of the present invention is to provide a sanitary napkinwith means to direct the flow of menses toward the ends of the napkin ata faster rate than toward the sides.

Briefly stated, in accordance with one aspect of this invention there isprovided a sanitary napkin having an uppermost absorptive layer which isadapted to promote lengthwise flow of fluid to be absorbed and whichcomprises a multiplicity of plies of cellulosic webs in face-tofacecontact and oriented perpendicularly with respect to the plane of theface of the napkin. The layer has substantially all of its pliesextending substantially lengthwise of the napkin in at least the centraltransverse region thereof, the outermost edges of the plies of the layerbeing contiguous to the face of the napkin to be placed next to the bodyof the user.

While the specification concludes With claims particularly pointing outand distinctly claiming the subject matter which is regarded as thepresent invention, it is believed that the invention will be betterunderstood from the following description taken in connection with theaccompanying drawing, in which:

FIGURE 1 is a perspective view, partly broken away, of a folded sanitarynapkin utilizing the present invention;

FIGURE 2 is an enlarged section of the sanitary napkin illustrated inFIGURE 1 taken along the line 22;

FIGURE 3 is a perspective view of an alternative emice bodiment of theflow directing layer of FIGURES 1 and 2; and

FIGURE 4 is a section of the alternative embodiment of FIGURE 3 takenalong line 44.

Referring to FIGURE 1, there is shown a sanitary napkin having anabsorbent pad indicated generally at 11 and comprising a multiplicity ofplies, the pad 11 being partly cut away to clarify its construction. Aswith other sanitary napkins, an outer wrap 12 of gauze or similartextile material of greater length than the pad 11 and ex tending beyondeach end of the latter is utilized to enclose the absorbent pad 11 andto provide means by which the catamenial device can be supported in use.The gauze wrap 12 is depicted with the lengthwise edges 12a and 12b inposition and overlapped on thelower face of the pad 11. The point ofoverlap on the pad is not critical insofar as this invention isconcerned and may be placed where thought most practical in view ofother considerations. A moisture impermeable membrane 13 is providedunder the superposed absorbent layers of the pad 11. The membrane 13 isadapted to serve as a shield which prevents liquid strike-through orspotting at the bottom of the napkin, and may be constructed from anyflexible impermeable material such as polyethylene having a thickness ofapproximately /2 to 1 /2 mils.

Directly over the membrane 13 is a lower layer or course of theabsorbent pad 11. This layer may comprise lamina 14 of a suitableabsorbent product such as a multiplicity of plies of crepee paper or,preferably, a thickness of airfelt. This absorbent lamina extends to thefull planar dimensions of the pad and is sized to have sufficientabsorptive capacity to make it well adapted for use in the catamenialfield. It has been found that airfelt which is approximately 4" thick issuitable material for the absorbent lamina. In a pad having facedimensions of approximately 2.5" x 7.0", airfelt weighing 3.4 grams hasan absorptive capacity of approximately 50 grams of water under nomechanical pressure.

The uppermost course of the absorbent pad 11 is a flow direction controlelement or layer 15. The layer 15 as shown in FIGURE 1 also iscoextensive with the length and width of the pad, and comprises amultiplicity of plies of cellulose webs in face-to-face contact, withthe plane of each ply being perpendicular to the planes of the upper andlower faces of the napkin and extending substantially longitudinally ofthe pad. While it is possible to derive some of the benefits of thisinvention when the layer 15 is smaller than (not coextensive with) thebalance of the pad 11, maximum benefits are attained by making the facedimensions of the layer correspond to. those of the pad.

Preferably the material constituting the layer 15 should be a lightbasis weight (air dry, in the range of 5 to 15 pounds per ream of 3000square feet before creping) embossed crepe paper with the machinedirection thereof parallel to its depth. It has been found that thelayer 15 should preferably contain 50 to 60 plies per inch of width andshould be about 4- /2" in depth. The layer 15, for example, has beenmade from a stack of a sub: stantial number of superimposed plies ofembossed creped paper having a basis weight (as stated above) of 10pounds per ream. The plies had a length of about 6" and the stack wasapproximately 2" high. Slices of about thickness were cut lengthwisefrom the stack so as to form a plurality of layers 2" wide, 6" long and/8" deep.

Prior to use, the napkin illustrated in FIGURE 1 is enclosed completelyin the gauze Wrapping. Then the device is applied with the layer 15 in aposition whereby the liquid to be absorbed by the device first entersthat layer, i.e., with the face 11a of the pad next to the body of theuser. Because of the orientation of the plies constituting the layer 15,the portion of the menses which is not absorbed by the plies themselvesis directed substantially in the longitudinal direction of the device,the spread of flow being in the planes between theindividual plies ofpaper, so that such flow is primarily toward the ends and into thenapkin. Due to the influence of such orientation, therefore, flow towardthe side of the napkin is curtailed and consequently a greaterpercentage of the absorptive capacity of the pad will be utilized priorto the time that in-use failure thereof occurs.

FIGURE 2 shows an enlarged lateral cross-sectional view of the assemblednapkin illustrated in FIGURE 1. Here the orientation of the plies of thelayer is clearly shown to be vertical or normal to the plane of the faceof the napkin. The impervious membrane 13 is coextensive with the lengthand width of the lamina 14- and layer 15, but it should be understoodthat these dimensions are not critical. The membrane 13 could beextended in length and in width in order to cause it to cover the sideand/or end edges of the absorbent material in the pad so as to give thewearer additional protection against failure of the device.Alternatively, the impermeable membrane may be made smaller than thelargest planar dimensions of the pad, in which case it would preferablybe centered so as to provide the maximum protection against liquidstrike-through.

In FIGURE 3 there is shown an alternative construction for the flowdirection control layer 15, utilizing a spirally wound slice 15a madefrom an annular roll of the absorbent tissue desired. Preferably for usewith a pad 11 of 2" x 6" face dimension the initial roll should have anouter diameter of about 4%" and an inner diameter of approximately 2%".The slice or layer 15a is desirably in the range of 1" to /2" in depth,has to convolutions of the tissue per inch of diameter in excess of itsinner diameter and can be severed from a flattened roll of material byutilizing cutting means which are well known to those skilled in theart. After the slice has been obtained, it is retained in the elongatedor flattened shape illustrated in which sides 16 and 17, which areultimately intended to be placed contiguous to the side edges of the pad11, are pressed inwardly. It will be observed that when the spiral layer15a is thus formed, the plies of the web comprising the layer areoriented as shown in FIGURE 4, in a direction normal to the plane of itsface. Moreover, the direction in which the plies extend is substantiallyparallel to the flattened side edges 16 and 17, at least over asubstantial portion of the central transverse region of the layer.

In use, the layer illustrated in FIGURES 3 and 4 may be placed atop theabsorbent layer 14 of the pad 11, centered thereon and oriented so as toplace the flattened sides 16 and 17 of the slice in parallelism wtih theside edges of the balance of the pad 11. It will be understood from theforegoing that in the sanitary napkin formed with the spiral layer 15aillustrated in FIGURE 3, small portions of the absorbent material 14will not be covered by the spiral layer, but this does not significantlyaffect the performance of the napkin.

The statements made previously with respect to the performance of thelayer 15 of the embodiment of FIG URES l and 2 are equally applicable tolayer 15a, since the modified construction of FIGURE 3 also promotes thespread of flow in the longitudinal direction of the napkin and therebylimits flow in the lateral direction thereof. Consequently, thealternative embodiment flow directional device is also useful inincreasing the effective absorptive capacity of a sanitary napkin.

Many modifications of the above invention may be used and it is notintended to hereby limit it to the particular embodiments shown ordescribed. The terms used in describing the invention are used in theirdescriptive sense and not as terms of limitation, it being intended thatall equivalents thereof be included within the scope of the appendedclaims.

What is claimed is:

1. A sanitary napkin for placement next to the body of the user, saidnapkin having a plurality of courses of absorptive material, at leastone of said courses comprising an absorptive layer adapted to promotelengthwise flow of fluid to be absorbed by the napkin, said layercomprising a multiplicity of plies of cellulosic webs in face-to-facecontact and normal to the plane of the face of said napkin,substantially all of said plies extending substantially lengthwise ofsaid napkin in at least the central transverse region thereof, theoutermost edges of said plies of said layer being contiguous to theportion of said napkin to which the fluid to be absorbed is firstsupplied.

2. In a sanitary napkin having a plurality of layers of absorptivematerial, an absorptive layer adapted to promote lengthwise flow offluid to be absorbed by the napkin, said layer comprising a multiplicityof plies of cellulosic webs containing about to about 60 plies per inchof width, said plies being in face-to-face contact and normal to theplane of the face of said napkin, substantially all of said pliesextending substantially lengthwise of said napkin in at least thecentral transverse region thereof, the outermost edges of said plies ofsaid layer being contiguous to the portion of said napkin to which thefluid to be absorbed is first supplied.

3. The sanitary napkin of claim 2 in which said layer has a depth ofabout /4" to about /2".

4. The sanitary napkin of claim 1 in which said plies compriseconvolutions of creped paper.

5. In an absorbent bandage, a pad having a multiplicity of layers ofmaterials of which the bottom layer is a thin flexible waterproof film,at least one intermediate layer is a thickness of airfelt, and theuppermost layer is l a flow spreading element comprising a multiplicityof References Cited in the file of this patent UNITED STATES PATENTS2,917,049 Delaney Dec. 15, 1959 2,952,259 Burgeni Sept. 13, 1960 FOREIGNPATENTS 883,695 Great Britain Dec. 6, 1961

1. A SANITARY NAPKIN FOR PLACEMENT NEXT TO THE BODY OF THE USER, SAIDNAPKIN HAVING A PLURALITY OF COURSES OF ABSORPTIVE MATERIAL, AT LEASTONE OF SAID COURSES COMPRISING AN ABSORPTIVE LAYER ADAPTED TO PROMOTELENGTHWISE FLOW OF FLUID TO BE ABSORBED BY THE NAPKIN, SAID LAYERCOMPRISING A MULTIPLICITY OF PLIES OF CELLULOSIC WEBS IN FACE-TO-FACECONTACT AND NORMAL TO THE PLANE OF THE FACE OF SAID NAPKIN,SUBSTANTIALLY ALL OF SAID PLIES EXTENDING SUBSTANTIALLY LENGTHWISE OFSAID NAPKIN IN AT LEAST THE CENTRAL TRANSVERSE REGION THEREOF, THEOUTERMOST EDGES OF SAID PLIES OF SAID LAYER BEING CONTIGUOUS TO THEPORTION OF SAID NAPKIN TO WHICH THE FLUID TO BE ABSORBED IS FIRSTSUPPLIED.